Solid rocket engine thrust regulation and control system and method based on microwave field

Abstract

The invention discloses a solid rocket engine thrust control system and method based on a microwave field. The solid rocket engine thrust control system comprises a combustion chamber shell, an annular heat insulation layer arranged around the inner wall of the combustion chamber shell and an annular grain. An empty runner is formed in the middle of the grain; the inner side of the front end of the combustion chamber shell is connected with the heat insulation layer and the igniter; the igniter is mounted on the inner wall of the grain; the gas outlet end of the combustion chamber shell is sequentially provided with a spray pipe convergent section, a spray pipe throat and a spray pipe expansion section. A pressure sensor, a temperature sensor and a force transducer are distributed on the outer side of the expansion section of the spray pipe, and the pressure sensor, the temperature sensor and the force transducer transmit acquired engine performance parameters to a monitoring terminal through electric signals; the monitoring terminal outputs electric signals to the impedance converter and the microwave power supply according to working condition requirements, the intensity of a microwave field is changed, and thrust regulation and control of the solid rocket engine are achieved. The size of microwave output is adjusted according to working conditions, and thrust regulation and control of the solid rocket engine are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of rocket engines, and in particular to a solid rocket engine thrust control system and method based on a microwave field. Background Art

[0002] The thrust of a solid rocket engine directly determines the acceleration and load capacity of the rocket, and has a key impact on the rocket's flight trajectory and flight speed. However, once a traditional solid rocket engine is ignited, the propellant combustion process cannot be stopped, resulting in the inability to adjust the engine's output thrust, limiting its flexibility.

[0003] At present, there are two main ways of reasoning and adjustment based on the working principle:

[0004] 1. Change the nozzle throat area.

[0005] 2. Control the combustion process of solid propellant. Changing the throat area will cause very serious ablation problems and is only suitable for engines with lower energy content, smaller size and shorter working time.

[0006] Therefore, new technologies that can dynamically adjust the propellant combustion process have become a research focus. Summary of the invention

[0007] In order to overcome the defects of the above-mentioned prior art, the present invention provides a solid rocket engine thrust control system and method based on microwave field, which feeds microwave energy into the solid rocket engine combustion chamber, utilizes microwave energy to enhance the combustion of solid propellant, and collects the performance parameters of the solid rocket engine during operation through pressure sensors, temperature sensors and force sensors. The collected data is transmitted to a monitoring terminal, and the monitoring terminal adjusts the microwave output size according to the working conditions, thereby realizing thrust control of the solid rocket engine. This method can effectively avoid the shortcomings of existing thrust control measures such as low combustion efficiency and unstable thrust output.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A solid rocket engine thrust control system based on a microwave field, comprising a microwave generating device;

[0010] The grain of the solid rocket engine is a ring-shaped column structure with a hollow flow channel, one end of the hollow flow channel is arranged with the microwave field generating device, and the other end is connected to the combustion chamber; the microwave generating device generates microwaves and forms a microwave field in the hollow flow channel;

[0011] The combustion chamber is provided with a sensor to monitor the working state of the solid rocket engine, and the microwave field intensity is increased when the engine thrust needs to be increased, and the microwave field intensity is reduced when the engine thrust needs to be reduced.

[0012] The combustion chamber comprises a nozzle convergent section, a nozzle throat, and a nozzle expansion section which are arranged in sequence, and the sensor is arranged in the nozzle expansion section;

[0013] The sensors include a pressure sensor, a temperature sensor and a force sensor. The higher the pressure and the higher the temperature, the greater the thrust generated by the engine. The three sensors are interrelated. The purpose of arranging the three sensors is to improve the detection accuracy and obtain more accurate engine performance.

[0014] The charge is installed in the combustion chamber shell, a heat insulation layer is arranged on the inner wall of the combustion chamber shell, and the igniter is arranged at one end of the hollow flow channel away from the combustion chamber;

[0015] The igniter is arranged around the emitting head of the microwave generating device;

[0016] The microwave generating device comprises a microwave power supply, a microwave generator, an impedance converter and a waveguide; the microwave power supply is a current adjustable power supply, the impedance converter is arranged at the transmitting end of the microwave generator, and the waveguide is the transmitting head of the microwave generating device, which is installed at the end of the hollow flow channel away from the combustion chamber, and transmits the microwave after impedance matching into the hollow flow channel;

[0017] In the case of a circular grain, the radius of the initial hollow flow channel is one tenth of the grain radius. Other types of grains need to be designed according to their specific shapes.

[0018] The inner side of the heat insulation layer is in close contact with the grain; the grain is distributed in a side-burning manner, and a microwave field with adjustable intensity is distributed in the middle flow channel; the combustion chamber shell is ignited from the inside, which is equivalent to a microwave field with adjustable intensity distributed from the middle flow channel in the direction from the inside to the combustion chamber shell;

[0019] The powder column contains metallic aluminum;

[0020] The high-pressure and high-flammability gas generated after the combustion of the propellant column enters the nozzle throat through the nozzle convergence section, and is then discharged into the atmosphere through the nozzle expansion section.

[0021] The expansion section of the nozzle expansion section has an angle of 6°-12°.

[0022] The microwave power supply is connected to the microwave generator, and the microwave power generated by the magnetic flux tube in the microwave generator is controlled by controlling the output current of the microwave power supply; the microwave outlet of the microwave generator is connected to the inlet of the impedance converter and is cooled by a heat exchanger; the impedance converter is responsible for matching the impedance of the microwave generator with the impedance of the solid rocket engine to provide a wider microwave working range; the impedance converter outlet is connected to the inlet of the waveguide, and the matched microwaves enter the solid rocket engine through the waveguide and establish a microwave field in the flow channel.

[0023] The waveguide is connected to the combustion chamber shell in the following manner:

[0024] If the combustion chamber shell is made of metal, holes should be opened at the connection to allow microwaves to enter;

[0025] If the combustion chamber shell is made of composite material, no holes are required.

[0026] Metals reflect microwaves, while composite materials can transmit microwaves. Therefore, when using metal materials, holes need to be opened to allow the generated microwave plasma to enter the combustion chamber and establish a microwave field.

[0027] A control method for a solid rocket engine thrust control system based on a microwave field, comprising the following steps;

[0028] The establishment of microwave field can be divided into cold start and hot start;

[0029] Cold start microwave field: Before the engine is ignited, the initial microwave field intensity is determined according to the operating conditions, and the microwave power supply, microwave generator and impedance converter are pre-set and started. The generated microwaves enter the engine through the waveguide and establish an initial microwave field in the flow channel. An external microwave source is used to discharge in the resonant cavity to form a suspended plasma. After the plasma enters the combustion chamber casing, it will be reflected by the metal and cannot penetrate the metal. The grain contains metallic aluminum, and a microwave field is established in the flow channel in the middle of the grain.

[0030] Then, the igniter is started to ignite the propellant grain, causing it to burn in the microwave field. The real-time working conditions of the engine are collected through the pressure sensor, temperature sensor and force sensor and transmitted to the control terminal. The control terminal outputs an electrical signal to change the working parameters of the microwave power supply and impedance converter according to the required thrust change, thereby changing the intensity of the microwave field in the engine and realizing the thrust control of the solid rocket engine. The output power and impedance of the microwave power supply can affect the output microwave plasma intensity, thereby changing the intensity of the microwave field in the flow channel. The greater the power and the smaller the impedance, the higher the intensity of the microwave field generated.

[0031] Hot start microwave field: After the engine is ignited normally and enters the working state, the engine working performance data is collected through the pressure sensors, temperature sensors and force sensors distributed on the nozzle expansion section. The collected data is transmitted to the control terminal in the form of electrical signals. The control terminal sets the working parameters of the microwave power supply and impedance converter according to the working conditions, and starts through electrical signals. Under the excitation of the microwave power supply, the microwave generator and heat exchanger enter the working state. The generated microwaves are matched by the impedance converter and fed into the working engine combustion chamber through the waveguide to establish a microwave field. The microwave field intensity is subsequently adjusted according to the engine working conditions to achieve thrust control of the solid rocket engine.

[0032] According to the actual thrust requirements, the microwave power supply, microwave generator, impedance converter and waveguide components can be replaced to achieve microwave fields in different working ranges.

[0033] Beneficial effects of the present invention:

[0034] The present invention feeds microwave energy into the combustion chamber of a solid rocket engine, utilizes microwave energy to enhance the combustion of solid propellant, and collects performance parameters of the solid rocket engine during operation through a pressure sensor, a temperature sensor, and a force sensor. The collected data is transmitted to a monitoring terminal, and the monitoring terminal adjusts the microwave output size according to working conditions, thereby realizing thrust control of the solid rocket engine. This method can effectively avoid the shortcomings of existing thrust control measures such as low combustion efficiency and unstable thrust output. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0036] In the attached drawing: 1-combustion chamber casing, 2-thermal insulation layer, 3-igniter, 4-propellant charge, 5-nozzle convergence section, 6-nozzle throat, 7-nozzle expansion section, 8-pressure sensor, 9-temperature sensor, 10-force sensor, 11-waveguide, 12-impedance converter, 13-heat exchanger, 14-microwave generator, 15-microwave power supply, 16-monitoring terminal. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0038] As attached Figure 1 As shown, the present invention is a solid rocket engine thrust control system and method based on microwave field. The system includes a combustion chamber shell 1, a heat insulation layer 2, an igniter 3, a propellant grain 4, a nozzle convergence section 5, a nozzle throat 6, a nozzle expansion section 7, a pressure sensor 8, a temperature sensor 9, a force sensor 10, a waveguide 11, an impedance converter 12, a heat exchanger 13, a microwave generator 14, a microwave power supply 15, and a monitoring terminal 16.

[0039] The front end of the combustion chamber shell 1 is connected to the waveguide 11 outlet, and the inner side of the combustion chamber shell 1 is connected to the heat insulation layer 2 and the igniter 3; the inner side of the heat insulation layer 2 is in close contact with the charge 4; the charge 4 is distributed in a side combustion manner, and a microwave field with adjustable intensity is distributed in the middle flow channel. The right side of the charge 4 is connected to the nozzle convergence section 5, the nozzle throat 6, and the nozzle expansion section 7 in sequence. The charge 4 structure is a hollowed-out cylinder, and the hollowed-out part is the flow channel.

[0040] A pressure sensor 8, a temperature sensor 9, and a force sensor 10 are distributed on the outside of the nozzle expansion section 7 to monitor the working status of the engine; the pressure sensor 8, the temperature sensor 9, and the force sensor 10 transmit the collected engine performance parameters to the monitoring terminal 16 through electrical signals; after the monitoring terminal 16 obtains the current real-time working condition of the engine, it outputs electrical signals to the impedance converter 12 and the microwave power supply 15 according to the working condition requirements, changes the microwave field intensity, and realizes thrust control of the solid rocket engine.

[0041] The microwave power supply 15 is connected to the microwave generator 14, and the microwave power generated by the magnetic flux tube in the microwave generator 14 is controlled by controlling the output current of the microwave power supply 15; the microwave outlet of the microwave generator 14 is connected to the inlet of the impedance converter 12 and is cooled by the heat exchanger 13; the impedance converter 12 is responsible for matching the impedance of the microwave generator 14 with the impedance of the solid rocket engine to provide a wider microwave working range; the outlet of the impedance converter 12 is connected to the inlet of the waveguide 11, and the matched microwaves enter the solid rocket engine through the waveguide 11 and establish a microwave field in the flow channel.

[0042] Implementation Case 1

[0043] In this embodiment, the cold start microwave field is used. First, the initial microwave field intensity is determined according to the engine working condition requirements. The microwave power supply 15, the microwave generator 14 and the impedance converter 12 are pre-set according to the required microwave field intensity. After the setting is completed, the microwave power supply 15 and the impedance converter 12 are started, so that the microwave generator 14 generates microwaves. The heat exchanger 13 enters the working state with the start of the microwave generator 14, ensuring that the working temperature of the microwave generator 14 is within the tolerance range of the magnetic flux tube. The microwave generated by the microwave generator 14 enters the waveguide 11 after matching and adjustment through the impedance converter 12. Under the constraint of the waveguide 11, the microwave enters the engine and establishes an initial microwave field in the flow channel. Then, the igniter 3 is started to ignite the propellant grain 4, and the grain 4 begins to burn in the microwave field. The high-temperature and high-pressure gas generated by the combustion flows through the nozzle convergence section 5, the nozzle throat 6, the nozzle expansion section 7 in sequence through the flow channel and finally discharges from the engine.

[0044] The pressure, temperature and thrust of the engine exhaust are collected through the pressure sensor 8, temperature sensor 9 and force sensor 10 distributed on the nozzle expansion section 7. The acquired data are transmitted to the control terminal 16 in the form of electrical signals to monitor the working status of the engine in real time. At the same time, the control terminal 16 can output electrical signals to the microwave power supply 15 and the impedance converter 12 according to the required thrust changes, so as to change the microwave power output by the microwave generator 14, and finally change the intensity of the microwave field in the engine to realize the thrust control of the solid rocket engine.

[0045] Implementation Case 2

[0046] In this embodiment, the microwave field is hot-started. In this case, the microwave field is turned on when the engine is in working state, as follows:

[0047] First, the igniter 3 is started to ignite the charge 4, and the solid rocket engine enters the working state. The high-temperature and high-pressure combustion gas generated by the combustion of the charge 4 flows through the nozzle convergence section 5, the nozzle throat 6, and the nozzle expansion section 7 through the flow channel in sequence, and finally exits the engine. The pressure sensor 8, the temperature sensor 9, and the force sensor 10 distributed on the nozzle expansion section 7 collect the engine working performance data, and transmit the collected data to the control terminal 16 through an electrical signal. After obtaining the real-time data of the engine, the control terminal 16 sets the working parameters of the microwave power supply 15 and the impedance converter 12 according to the working conditions, and then starts the microwave power supply 15 and the impedance converter 12 through an electrical signal. Under the excitation of the microwave power supply 15, the microwave generator 14 and the heat exchanger 13 enter the working state. The generated microwave is matched by the impedance converter 12 and then fed into the combustion chamber of the working engine through the waveguide 11. The fed microwave interacts with the burning propellant, promotes the generation of free electrons in the balanced flame, generates more plasma in the flame combustion zone, improves the combustion efficiency of the solid propellant, and thus increases the thrust. The subsequent process is the same as that in Case 1 and will not be repeated.

Claims

1. A solid rocket engine thrust control system based on microwave field, characterized in that: including a microwave generating device; The grain (4) of the solid rocket engine is a ring-shaped column structure with a hollow flow channel, one end of the hollow flow channel is arranged with the microwave field generating device, and the other end is connected to the combustion chamber; the microwave generating device generates microwaves and forms a microwave field in the hollow flow channel; The combustion chamber is provided with a sensor to monitor the working state of the solid rocket engine, and the microwave field intensity is increased when the engine thrust needs to be increased, and the microwave field intensity is reduced when the engine thrust needs to be reduced.

2. The solid rocket engine thrust control system based on microwave field according to claim 1, characterized in that: The combustion chamber comprises a nozzle convergent section (5), a nozzle throat (6), and a nozzle expansion section (7) which are arranged in sequence, and the sensor is arranged in the nozzle expansion section (7); The sensors include a pressure sensor (8), a temperature sensor (9) and a force sensor (10), and the higher the pressure and the higher the temperature, the greater the thrust generated by the engine; The charge (4) is installed in the combustion chamber shell (1), a heat insulation layer (2) is provided on the inner wall of the combustion chamber shell (1), and the igniter (3) is arranged at one end of the hollow flow channel away from the combustion chamber; The igniter (3) is arranged around the emitting head of the microwave generating device; The microwave generating device comprises a microwave power source (15), a microwave generator (14), an impedance converter (12) and a waveguide (11); the microwave power source (15) is a current adjustable power source, the impedance converter (12) is arranged at the transmitting end of the microwave generator (14), and the waveguide (11) is the transmitting head of the microwave generating device, which is installed at one end of the hollow flow channel away from the combustion chamber to send the microwave after impedance matching into the hollow flow channel; When the drug column (4) is a circular drug column, the radius of the initial hollow flow channel is one tenth of the radius of the drug column (4).

3. A microwave field-based solid rocket engine thrust control system according to claim 2, characterized in that: The inner side of the heat insulation layer (2) is in close contact with the charge (4); the charge (4) is distributed in a side-burning manner, and a microwave field with adjustable intensity is distributed in the middle flow channel; The drug column (4) contains metallic aluminum; The high-pressure and high-flammability gas generated after the combustion of the charge (4) enters the nozzle throat (6) through the nozzle convergence section (5) and is then discharged into the atmosphere through the nozzle expansion section (7).

4. The solid rocket engine thrust control system based on microwave field according to claim 2, characterized in that: The expansion section angle of the nozzle expansion section (7) is 6°-12°.

5. The solid rocket engine thrust control system based on microwave field according to claim 2, characterized in that: The microwave power source (15) is connected to the microwave generator (14), and the microwave power generated by the magnetic flux tube in the microwave generator (14) is controlled by controlling the output current of the microwave power source (15); the microwave outlet of the microwave generator (14) is connected to the inlet of the impedance converter (12), and is cooled by the heat exchanger (13); the impedance converter (12) is responsible for matching the impedance of the microwave generator (14) with the impedance of the solid rocket engine to provide a wider microwave working range; the outlet of the impedance converter (12) is connected to the inlet of the waveguide (11), and the microwave after matching enters the solid rocket engine through the waveguide (11), and establishes a microwave field in the flow channel.

6. The microwave field-based solid rocket engine thrust control system according to claim 2, characterized in that: The waveguide (11) is connected to the combustion chamber casing (1) in the following manner: If the combustion chamber shell (1) is made of metal material, a hole is opened at the connection portion to allow microwaves to enter; If the combustion chamber shell (1) is made of a composite material, no holes need to be drilled.

7. A control method for a solid rocket engine thrust control system based on a microwave field according to any one of claims 1 to 6, characterized in that: The steps include: The establishment of microwave field can be divided into cold start and hot start; Cold start microwave field: before the engine is ignited, the initial microwave field intensity is determined according to the working condition requirements, and the microwave power supply (15), the microwave generator (14) and the impedance converter (12) are pre-set and started. The generated microwaves enter the engine through the waveguide (11) and establish an initial microwave field in the flow channel; an external microwave source is used to discharge in the resonant cavity to form a suspended plasma. After the plasma enters the combustion chamber shell (1), it will be reflected by the metal and cannot penetrate the metal. The grain (4) contains metal aluminum, and a microwave field is established in the flow channel in the middle of the grain (4). Then, the igniter (3) is started to ignite the propellant grain (4) so ​​that it burns in the microwave field, and the real-time working condition of the engine is collected through the pressure sensor (8), the temperature sensor (9) and the force sensor (10) and transmitted to the control terminal (16). The control terminal (16) outputs an electrical signal according to the required thrust change to change the working parameters of the microwave power supply (15) and the impedance converter (12), thereby changing the intensity of the microwave field in the engine and realizing the thrust control of the solid rocket engine; Hot start microwave field: After the engine is normally ignited and enters the working state, the engine working performance data is collected through the pressure sensor (8), temperature sensor (9) and force sensor (10) distributed on the nozzle expansion section (7), and the collected data is transmitted to the control terminal (16) in the form of electrical signals. The control terminal (16) sets the working parameters of the microwave power supply (15) and the impedance converter (12) according to the working condition requirements, and starts through the electrical signal. Under the excitation of the microwave power supply (15), the microwave generator (14) and the heat exchanger (13) enter the working state, and the generated microwave is matched by the impedance converter (12) and fed into the working engine combustion chamber through the waveguide (11), thereby establishing a microwave field. The microwave field intensity is subsequently adjusted according to the engine working condition requirements to achieve thrust control of the solid rocket engine.

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